US President Donald Trump's sudden decision to withdraw US forces from Syria is a reminder that this is not an ordinary time in Washington.

The political establishment and Congress have been forcing the president's hand on key foreign policy challenges, from Russia to Saudi Arabia, but Trump had a trick up his sleeve on Syria. He has reasserted his executive power at home by effectively moving to limit US power abroad.

Now 2,000 US troops are scheduled to withdraw from northern Syria within the next 100 days, leaving behind much uncertainty for both allies and foes.

What this tells us about the Trump administration
There is no simple explanation for the timing and rationale of this decision. Some argue that Trump is using it as a distraction from his legal troubles in the US or that he has been influenced by his phone call with Turkish President Recep Tayyip Erdogan last Friday. Others assert that a grand deal in Syria is in the making and the US sold out its Kurdish partners.

Speculations aside, Trump has been talking about withdrawal for a while now as he does not see any financial or strategic value in keeping US forces in Syria. Last March, the president casually announced during a rally that US forces will "be coming out of Syria, like, very soon".

The Pentagon and the State Department then coalesced their efforts to convince the commander-in-chief that the US must stay, but in April he gave the military six months to finish the job against the Islamic State of Iraq and the Levant (ISIL, also known as ISIS). Earlier this month, the US-backed Kurdish-led Syrian Democratic Forces (SDF) captured the town of Hajin, the last ISIL-controlled urban area. While ISIL remains a threat, Trump believes the necessary time given to the military was enough and US troops should come home.

His decision is very much an indication of how detached Trump has become from his national security team. In the past few months, the conservative wing of his administration led by National Security Adviser John Bolton and the military wing led by Defence Secretary James Mattis made different arguments for keeping US forces in Syria.

Bolton, who has been advocating for months the idea of expanding the US mission in Syria to deter Iran, now has absolutely nothing to show for it. He managed to convince Trump in September to agree on an indefinite US role in Syria. However, his idea of an "Arab NATO" was expectedly not feasible and Saudi Arabia seems unenthusiastic about funding a long-term US presence in northern Syria.

Mattis, on the other hand, has been warning of Bolton's adventurism that might risk confrontation with Iran and instead has been arguing that the US should stay in Syria to confront ISIL and push for a path towards conflict resolution. But he too seems to have become more isolated within the Trump administration, especially after he lost a key ally with the resignation of White House Chief of Staff John Kelly.

Trump's decision to pull out of Syria might widen the distrust between the White House and the military, which might have repercussions in other war zones like Afghanistan, where the president also believes the US withdrawal should be imminent.

The war and peace decisions are typically announced by the White House in consultations with key agencies and the Congress, but the way this decision was orchestrated reflects a deep division in Washington on this issue. Possible resignations from the Trump administration might be announced in the coming days, weeks and months as a result of this decision.

It is important to point out that US' policy on Syria has been failing dramatically in the past seven years and Trump might just have put it out of its misery. The balancing act between Turkey and the Kurds did not achieve necessarily any long-term conditions for stability in northern Syria.

Washington can neither make a deal nor confront Moscow in Syria nor does it seem invested in advancing a UN-led political process. The new US envoy to Syria James Jeffrey recently added confusion to US policy by stating that the Trump administration wants change in the Syrian regime not regime change. As the White House tacitly approved President Bashar al-Assad staying in power until the next Syrian presidential election in 2021, the US plan in Syria shifted to trying to hunker down and disrupt the Russian plan.

Some US officials continue to believe that the US can play a decisive role on the situation in Syria and remain in denial about the limits of US power in the Middle East. There is also some wishful thinking that Trump might once again change his mind on Syria after listening to his advisers, but this does not seem the case this time around.

What this means for the other players in Syria
Regardless of whether Trump's decision will stand or not, the reputation of his administration will most likely suffer, as it is increasingly being seen by allies around the world as erratic and unreliable. The fact that the US is letting down its Kurdish allies will make it difficult for other forces in the Middle East to trust it.

It is worth noting that the 2,000 US forces in Syria had no combative role and withdrawing them does not mean the US will lose its ability to launch air attacks when needed. But the symbolism of the withdrawal is significant when it comes to the strength of US commitment in Syria.

At the same time, the most obvious beneficiaries of Trump's decisions might face unforeseen difficulties, as a result of the US withdrawal. Trump's move throws the burden of resolving the situation in northern Syria on Russia and Turkey, which might lead to a crack in their alliance as they struggle to fill the vacuum left by the US.

SDF will most probably move closer to Russia now and expand its engagement with Damascus, potentially surrendering border posts on the Turkish border to the Syrian regime as a way to establish a buffer zone against possible Turkish incursions.

As for Iran, the US withdrawal from Syria might weaken its argument for an open-ended stay in the country. And the Trump administration might still be able to strike a deal with Russia to curtail Iranian presence in Syria.

The Trump administration has a lot to explain in the coming weeks regarding the timeline of this withdrawal and what US allies should expect moving forward. An imminent US withdrawal without setting the necessary conditions might lead to a backlash or in the worst-case scenario - an open confrontation between Turkish and Kurdish forces.

The US had no strategy of how to stay in Syria, now it is clear it has no strategy of how to leave.